Volleyball is like other team sports in that there are specific defensive and offensive formations that are determined by who has the ball. But unlike other team sports where possessions may last 20 seconds or several minutes, possessions in volleyball may last only two or three seconds. Consequently, players must move very quickly from their defensive assignments to their offensive assignments. This movement, from defense to offense and vice versa, is called "transitioning." Quick, smooth transitions are imperative if your team hopes to play good volleyball.
A team is on "defense" -- that is, they are in their defensive positions -- whenever the opponent is preparing to attack. Consequently, you must be in your assigned position whenever the ball is in your opponents' court or whenever your team serves, because the ball will be in your opponent's court soon. (When the opponent serves, you are not in defense, because the first thing your team will do is attack the ball.)
At the beginning level of play, where hard driven balls are few and far between and there is little or no specialization, most teams use a "middle-up" defense with no blockers. In this particular defensive scheme, the setter (who is in middle front or switches to middle front) is at the net, with the other two front row players positioned near the sidelines, just behind the 3m line. The middle-back player is "up" at the 3m line (hence the name "middle-up"), while the other two back-row players split the back half of the court. These positions create a "W," not including the setter. Players generally stay in these positions throughout each rally -- that is, there are few defensive adjustments to make according to where the opponent sets the ball, nor are there many differences between defense and offense.
Most mid- and upper-level teams, because the opposing hitters are better, use all three front-row players as blockers. More often than not, these teams are also running a 6-2 offense, which means the setter is coming from right back, though some teams elect to use a 4-2, with the setter playing in middle or right front. In either case, the starting defensive positions (or "base" positions) for a middle-back defense usually look like the diagram on the right.
The front row players are at the net, preparing to block. Back row players are relatively shallow in the court, in case the opponent bumps the ball back over on their first hit or "dumps" the second hit over the net. As soon as the the opponent sets the ball to one of their hitters, everyone will have to move these "base" positions to an assigned defensive responsibility.
A common strategy (but by no means the only strategy) for defending attacked balls include these general rules:
1. The blockers should position themselves so that no balls can be driven into the center of your court. Double block the outsides and single block the middle.
2. The offside blocker (meaning, the front-row player not involved in the block) will pick up all tips.
3. The outside back-row players must dig around the outside of the block.
4. Middle back positions him/herself in the "seam" of the block, usually a step or two cross-court.
Remember: The "standard" defense diagramed above, which commits the offside blocker to covering tips, is only one possible strategy. Some teams use a "rotation" defense, in which the outside back row player nearest the set moves forward to cover tips while the other defenders "rotate" to cover the vacated area. Other teams use a "perimeter" defense, meaning no one is assigned to cover tips; all four diggers position themselves along the perimeter of the court. Whichever defensive scheme your team elects to use, you must understand that the blockers and backrow defenders must work in unison to cover the court -- that is, diggers should position themselves so that they are not defending the same area as the block.
In addition, you should use a strategy that fits your team's personnel and your opponent's offensive tendencies. If you have terrific left side diggers, for instance, you should arrange your block so that it funnels hits to them. Or, if your opponent often tips down the line, you should use a rotation defense; if they tip to the center of the court, use the first defense mentioned above. If your opponent hardly ever tips, use a perimeter defense.
Downballs and freeballs
At most levels of play, your opponents will give your team lots of "downballs" and "freeballs." The distinction is important because it significantly alters defensive responsibilities. A downball is any set that your opponents can swing at but which they cannot attack with authority. If the blocker closest to the attacker recognizes that the hitter is not going to able to take a good swing at the ball, s/he yells, "Downball!" Both blockers stay down (hence, the term "downball") and back off one step to pick up tips or balls that carom off the net. The other four players (the offside blocker and three back-row defenders) position themselves in a slight umbrella shape, with the line digger staying relatively deep and the cross-court digger staying relatively shallow.
A freeball is any ball that the opponent will bump or set into your court. As soon as it is clear that your opponent cannot attack the ball at all, everyone yells, "Freeball." The setter releases from her/his defensive position, usually in right back, as soon as s/he realizes the opponent cannot attack the ball and sprints to her/his offensive position near middle front (the setter should never, ever pass a freeball). The remaining back-row players split the back court while all the blockers drop to the 3m line and prepare to hit. These transitions create a W formation, not including the setter. These are also your offensive positions (more about that in the next section).
Don't relax on freeballs! This is your team's best chance to score a point or get a sideout, so focus on moving your body to the ball and making a perfect pass to the setter.
1. Blockers must realize their job is not to stuff every hit; their job is to keep balls from being driven into certain areas of the court -- that is, they are blocking a zone, not the ball.
2. Whoever has tips -- whether it's a back row player or the offside blocker -- must stay low and run after every tipped ball. This frees the backrow players to worry only about driven balls.
3. Cross-court diggers must position themselves so that they can clearly see the ball and the attacker around the outside of the block. If they position themselves behind the block, where no balls can be driven at them, they become useless players.
4. Middle back players must first defend against hits through the seam of the block, but they must also be prepared to run after soft shots to the center of the court and balls that ricochet off the block.
5. Do not think of defense in terms of "tape-on-the-floor." Just get to your assigned position quickly and then react to every ball.
6. Call downballs and freeballs loudly and early. Move to the appropriate position quickly. Don't relax on freeballs.
7. In a freeball situation, make sure the setter never passes the ball.
8. Lastly, and most importantly, everyone must do the basic individual skills correctly: blockers must get their hands and forearms in the opponents' court, and diggers must be low and moving forward before the hitter contacts the ball.